The present invention relates to a process for modifying the surfaces of materials.
In recent years, modification or improvement of the surfaces of materials makes an important technology in various fields such as medical care, dyeing and adhesion. Particularly, in the medical field, it is difficult to find a material which simultaneously satisfies the dynamical characteristics and the biocompatibility of the surface thereof and, therefore, it has been attempted to modify the surface of a device made from a material which satisfies required dynamical characteristics, so as to impart a biocompatibility to the device surface.
Representative means for modifying the surface of a material are coating and discharge treatment.
There is proposed a process wherein an azido group is introduced to a compound having characteristics necessary for the modification of the surface of a material, the compound is coated on the material surface to be modified and it is fixed to the material surface through covalent bond by a photochemical reaction of azido group introduced to the compound. The proposed process utilizing a photochemical reaction of azido group has the advantage that the newly formed surface is very stable because the azido group-introduced compound is fixed to the material surface through covalent bond. However, the process has the disadvantages that characteristics desired to modify or improve vary depending on the purposes and the like and, therefore, various azido group-containing modifiers must be prepared by introducing azido group to every compound which has characteristics necessary for the desired modification, and that the process is not applicable to materials with which the nitrene group produced by photochemical reaction of azido group cannot form covalent bond. Also, if a compound which has characteristics desired for the modification of a material surface and to which azido group is introduced, or an aqueous or organic solvent solution thereof is not compatible with the material surface to be modified, it does not contact uniformly or close with the material surface and the azido group-containing compound is not fixed well to the material by photochemical reaction, resulting in unsatisfactory modification.
It is an object of the present invention to provide a process for modifying surfaces of materials, which is applicable with ease to various compounds having characteristics desired for the modification of material surfaces and to various materials to be modified, and which can firmly fix the compounds to the material surfaces.
The above and other objects of the present invention will become apparent from the description hereinafter.